MMW FINALS Flashcards
Arrangement of raw data into class
intervals and frequency
Frequency Distribution Table
either nominal or ordinal level of
measurement
Qualitative Data
Vertical bars that have no gaps
because of class boundaries
Histogram
Five-number summary
Minimum, lower quartile, median, upper quartile,
maximum
Box-and-Whisker Plot
Used when there are extreme values in the dataset,
Outliers
utliers lie beyond the ranges of values and can be determined by using:
lower quartile – 1.5IQR
upper quartile + 1.5IQR
presents the score values and their frequency of occurrence. When presented in a table, the score values are listed in rank order, with the lowest score value usually at the bottom of the table.
frequency distribution
The steps for constructing a frequency
distribution of grouped scores are as
follows:
- Find the range of the scores.
Range = Highest Score – Lowest Score - Determine the tentative number of classes (K).
𝐾 =1+[3.322(log 𝑁 )] - Determine the width of each class interval (i).
𝑖= 𝑅
𝐾 - List the interval, placing the interval containing the lowest score
value at the bottom. - Tally the raw scores into the appropriate class intervals.
- Add the tallies for each interval to obtain the interval frequency.
Displays data by using bars of equal
width on a grid. The bars may be vertical or horizontal. Bar graphs are used for comparisons.
Displays a bar for each category with
the length of each bar representing the frequency of that category.
Bar Graph
ordered from
highest to lowest
frequency.
A Pareto Chart
to show how data represent
portions of one whole or
one group.
Circle Graph (Pie Chart)
Notice that each sector is
represented by %
Circle Graph (Pie Chart)
joined by line segments to
show trends over
time.
Broken Line Graph
which points on
the line between the plotted
points also have meaning.
Sometimes, this is a “best fit”
graph where a straight line is
drawn to fit the data points.
Continuous Line Graph
Notice that the
independent variable is
on the x-axis, & the
dependent is on the y-
axis.
Continuous Line Graph
Uses pictures and
symbols to display data;
each picture or symbol
can represent more than
one object; a key tells
what each picture
represents.
Pictograph
A graph of data that is a set of points.
Scatter Plot
IQR (Interquartile Range)
Q1 – Lower Quartile
Q3 – Upper Quartile
A value that “lies outside” (is much smaller or larger than) most of the other values in a set of data
outlier
One way to determine if a data point is an outlier is to use the interquartile range (IQR) method.
Lower Boundary : Q1 – 1.5 IQR
Upper Boundary : Q3 + 1.5 IQR
formula Variance
S2 =
Where:
x – scores
- mean
n – number of samples
formula Standard Deviation
S =
Where:
x – scores
- mean
n – number of samples
The variance can be found by following these four steps
- Find the mean.
2.Subtract the mean from
each of the five
samples/observations. - Squaring these deviations
from the mean - Taking the average of these
squared deviations.
These are unit-less and are used
when one wishes to compare
the scatter of one distribution
with another distribution.
Measures of Relative Dispersion
It measures how many standard
deviation is above or below the
mean.
Standard Score
It is computed as
and the sample counterpart is
Standard Score
occurs when the values of variables appear at regular frequencies and often the mean, median, and mode all occur at the same point. If a line were drawn dissecting the middle of the graph, it would reveal two sides that
mirror one other.
symmetrical distribution
lack of symmetry
can be right skewed distribution or left skewed distribution
asymmetric distribution
is a measure or a criterion on how asymmetric the distribution of data is from the mean.
Skewness
is a method developed by Karl
Pearson to find skewness in a
sample using descriptive statistics
like the mean and mode.
Pearson Coefficient of skewness
Symmetrical distribution and mode occur when the values of variables occur at regular frequencies and the mean, median at the same point
Symmetrical distribution
(or right-skewed) distribution is
a type of distribution in which most values are clustered around the left tail of the distribution while the right tail of the distribution is longer
a positively skewed